Active electrical and optical cables are common solutions for high-speed data transfer between systems, such as connection between a computer and a peripheral device, two computers in a cluster, a switch to an endpoint, etc. An active electrical cable may contain electrical wiring and active electronic devices (electrical repeaters or retimers) at both ends, where each device communicates with one neighboring terminal system. An active optical cable may include a pair or multiple pairs of optical fibers with non-detachable optical modules on both sides. An optical module may convert the electrical signals at the cable's interface to optical signals on the fibers and vice versa.
Using active cables may create a challenge of testing the cable quality. Instead of loss data used to test regular passive cables, the important characteristic of an active cable is the bit error rate (BER) of the communication between the repeaters. This characteristic may need to be verified for a given active cable. However, compared to regular cable testing, the measurements involved may take much longer and may require expensive and complex equipment.